Clarifications

In this version, we further distilled our novelty into the princile of guest-delegation, provided motivation for such delegation through both theoritical analysis of virtualization and empirical evlauation of eixsting hypervisor-based approaches.

We also included evaluation on hypervisor-based approaches and latency sensitive real world applicaiotn in our paper.

Origin review summary

Ultimately, the paper was rejected due to concerns about incremental novelty, lack of deeper motivation for the design choices, and evaluation gaps (missing hypervisor-based comparisons). In future iterations, the reviewers recommend to further distill and emphasize the novel contributions of the approach, and including a clear threat model. The reviewers also suggest strengthening the novelty claims of the PEBS based hotness tracking, and enhancing evaluation with broader benchmarks and latency analysis.

v1

Clarifications on Significant Changes from Previous Version

In response to reviewer feedback about incremental novelty and design motivation, we have made the following substantial improvements:

1. Unified Theoretical Framework We have fully developed the "guest-delegation" principle as a cohesive theoretical framework underlying our approach, clarifying how this represents a paradigm shift rather than an incremental improvement over existing hyperivsor-based and kernel-based solutions.

2. Strengthened Motivation

   We have added detailed empirical analysis in Section 2.3 demonstrating the fundamental limitations of hypervisor-based approaches, including:

   • Quantitative measurement of TLB flushes and overhead (Tbl. 1)
   • Analysis of EPT-friendly PEBS scalability issues (Fig. 2)

3. Expanded Evaluation

   We have addressed key evaluation gaps by:

   • Adding direct comparisons with hypervisor-based approaches (TPP-H) across seven real-world workloads
   • Including latency analysis for interactive applications (Fig. 12), showing 23% reduction in tail latency

4. Clarified Novelty of PEBS Approach

   We have substantiated our claims about EPT-friendly PEBS with:

   • Technical explanation of previous architectural limitations (Section 2.3.2)
   • Analysis of isolation properties ensuring multi-tenant security
   • Context-switch-based sampling implementation that reduces CPU overhead by 16×

5. Added Threat Model Discussion Despite this is not the main focus of our paper, we have included a threat model in Section 7.2, addressing security considerations for untrusted guest code running in multi-tenant environments.